The present invention pertains to methods for depositing dielectric film on a substrate. More specifically, the invention pertains to high deposition rate PECVD TEOS processes. The invention is effective at producing high quality, low defect PECVD TEOS films.
TEOS (tri-ethoxy-organo-silicate) is a silicon-containing compound that is a liquid at room temperature. TEOS is used in many applications to deposit dielectric film on a substrate, e.g., in place of silane. TEOS is used in applications where conformality is required as silicon dioxide (or “TEOS oxide”) films deposited by TEOS chemical vapor deposition processes have good conformality. TEOS oxide is often deposited by a plasma enhanced deposition chemical vapor deposition (PECVD) process.
TEOS-based PECVD processes typically involve exposing a substrate to a process gas including TEOS and an oxidant such as oxygen or ozone. Most processes for depositing TEOS are low deposition rate processes, resulting in at most about 3000-4000 angstroms/min (on a bare substrate). It would be desirable to have high deposition rate processes for depositing TEOS films. However, to date, high deposition rate methods of depositing a silicon oxide films result in films with a high number of defects.
What are needed therefore are improved methods for depositing TEOS films.